Does the guilt really make guilty pleasures taste better?

…participants who had been primed for guilt both liked the candy more and said they would be willing to pay more for it than those primed with neutral words. Guilt also made the initial pleasurable reaction last longer—the guilt-primed participants remembered liking the candies more than neutral-primed participants.

And:

Neither Goldsmith nor her colleagues were surprised by the consistency of these results. “Guilt is linked with pleasure because often times when we experience guilt, we experience pleasure,” Goldsmith says. “I think for a lot of people these cognitive associations can form just based on what we called repeated coactivation. When pleasure’s activated, guilt is activated, and so in our brains, over time, those two become connected.”